Steam-engine governor



(No Model.) 3 Sheets-Sheet. 1.. E'. F. WILLIAMS. STEAM ENGINE GOVERNOR.

No. 408,158. Patented July 30, 1889.

(No Model.) 7 V 3 Sheets-Sheet 3. E. F. WILLIAMS. STEAM ENGINE GOVERNOR-Patented July so, 1889.

I 8mm 1 EJwzwFWaZZiawa N. PETERS. Phblv-Enh UNITED STATES PATENT OFFICE.

EDWIN F. WILLIAMS, OF CHICAGO, ILLINOIS.

STEAM-ENGINE GOVERNOR.

SPECIFICATION forming part of Letters Patent No. 408,153, dated July 30,1889.

Application filed October 5, 1888. Serial No. 287,324. (No model.)

T0 on whom it may concern:

Be it known that I, EDWIN F. \VILLIAMS, a citizen of the United cago, inthe county of Cook and State of Illinois, have invented a certain newand useful Improvement in Steai1i-Engi11e Governors, which is fully setforth in the followingspecification, reference being had to theaccompanying drawings, in which- Figure 1 represents an elevation of aconstruction embodying my invention; Fig. 2, a sectional view of thesame, taken on the line 1 1 of Fig. 1; Fig. 3, a view similar to Fig. 1,showing my invention in a modified form; Fig. 4, a plan view of theconstruction shown in Fig. 3, the rear portion thereof being in sectionupon the line 2 2 of said figure; and Fig. 5, a diagram illustrating theoperation of the device.

Like letters refer to like parts in all the figures of the drawings.

My invention relates to that class of steamengine governors in which theregulation is automatically effected by changing the position of aneccentric on the shaft, so as to give a greateror less degree ofeccentricity, properly conditioned to give a longer or shorter period ofopening to admit steam to the cylinder at each stroke.

My invention is applicable both to that class of engines wherein asingle valve operating upon a fixed seat is employed in connection withan eccentric of variable posi tions, and also to that class wherein amain valve operated by a fixed eccentric is employed in conjunction witha cut-off valve moving upon or in said main valve and controlled by asecond eccentric variable in its positioirwith relation to the shaft.

The object ofmy present invention is to provide a simple and effectivegoverning mechanism which shall be free from complication of parts, wellbalanced in the arrangement of parts, and free from friction.

To these ends my invention consists in certain novel features,which Iwill now proceed to describe, and will then particularly point out inthe claims.

In the drawings, A represents the main shaft of the engine, and B apulley orwheel keyed or otherwise secured thereon. This pulleyor States,residing at Chi-' wheel may or may not be employed as adriving-pulley,as desired.

0 represents the shiftingor variable eccentric, which is provided with aslot c, through which the shaft A passes, which slot permits theeccentric to move across the shaft in the manner hereinafterdescribed.

C represents an arm which supports the eccentric 0, one end of said armbeing pivoted to thepulley B, as shown at c, by means of a suitablepivot-bolt, its other end being formed in one piece with or secured tothe hub C of the eccentric C. At about ninety degrees from the arm C asecond arm 0 extends outward from the hub 0 I) represents a governor-armpivoted to the pulley B at (Z, and provided near its free end with anadjustable weight D. The free end of the arm D is connected to the arm 0by means of a spring E. The spring E is what is known as a strap or fiatspring, and its ends are secured to the arms D and c by means ofscrew-bolts e or other suitable means. It has preferably a normalcurvature, substantially such as is shown in the drawings.

F represents a coiled spring, one end of which is suitably connected tothe arm 0 its other end being connected to the rim of the pulley B bymeans of an adjusting-screw f, which serves to regulate the tension ofsaid spring.

As before stated, I have shown in Figs. 1 and 2 of the drawings, agovernor wherein the construction just described is adapted for use inconnection with a single valve engine, wherein the slide-valve worksupon a fixed seat and the regulation of the steam is effected by thedistance traveled by said valve. When the eccentric O is in the positionshown in Figs. 1 and 2, the valve operates to admit the maximum amountof steam to the cylinder, this maximum being of course determined by therelative proportions of the Valve and valveseat and their ports. Whenthe eccentric is moved over to the other extreme, the travel of thevalve is reduced to a minimum and is about equal to the lap, so thatpractically no steam is admitted to the cylinder. The variousintermediate positions of the eccentric between these two extremes givevarious intermediateamounts of steam to the cylinder, the point ofcut-off changing with each change in the position of the eccentric. Letit be supposed, for instance, that the engine is running at normal speedwith a load sufficient to maintain the parts in the position shown. Uponany diminution in this load the speed of the engine will increaseproportionately, and this increased speed will cause the weightedgovernor-arm D to move outward to a corresponding extent. This outwardmotion of the governor is against the centripetal force of the spring E,which spring serves as a link to transmit the motion of the arm D to theeccentric O. The eccentric C then moves inward, or, in other words, itscenter approaches the center of the shaft A, thereby diminishing itseccentricity. This movement takes place around the pivot c as a center.The decrease of the eccentricity correspondingly diminishes the travelof the valve, and consequently reduces the rate of speed until it againbecomes normal. Conversely, upon anyincrease in the load the speeddiminishes and thecentripetal action of the spring E overcomes thediminished centrifugal force of the governor-arm D, and the eccentric Ois moved outward to a corresponding extent, thus increasing the travelof the valve and bringing the speed of the engine up until it becomesnormal. It will thus be seen that the governor-arm D provides. acentrifugal force and the spring E a centripetal force, which act inopposition to each other, and which upon any change in the rate of speedof the engine so move the eccentric as to render. the speed normal. Thespring F, although supplying a portion of the centripetal force, isemployed chiefly for the purpose of providing a ready means foradjusting said force and is supplemental to the spring E. Thedifficulties attendant upon the adjustment of the force of a fiatspring, such as IE, will be at once apparent, and for this reason Iemploy the spring F, of adjustable tension, for increasing ordiminishing the centripetal force without necessitating any interferencewith the spring E. It will also be observed that the spring E, whileacting as a link to connect the governor-arm and eccentric, possessesVarious advantages over such a link, since all pivot-joints, with theirattendant friction and liability to wear loose, are done away with bythe employment of said spring. Moreover, the arrangement of parts issuch that the several elements balance each other and reduce thefriction at the various pivots to a minimum. The weighted governor-arm Dalso tends to hold the eccentric firmly in position and prevent anyvibrations thereof.

In Figs. 3 and 4 of the drawings I have shown a construction in which myimproved governor is applied to that class of engines in which a cut-offvalve separate and distinct from the main valve and moving thereon ortherein is employed. In this construction the elements are substantiallythe same as those just described, the eccentric O becoming the cut-offeccentric. 0 represents the eccentricstrap, and c theeccentric-rod,which leads to a rocker-arm, from which the cut-off valveis operated. G represents the main eccentric, which is fixed upon theshaft A, and is provided with a strap G and rod g, by means of which themain valve is operated. It will be observed that the eccentricity of thetwo eccentrics is opposite, this being the case because I have shown aconstruction adapted for use in connection with an intermediaterocker-arm for operating the cutoff valve, which rocker-arm reverses thedirection of motion of said valve with respect to its eccentric. If thisrocker-arm be omitted, the eccentrics will of course be arranged on thesame side of the shaft A. In this construction the main eccentric isfixed upon the shaft A, and consequently its center is at a fixeddistance from its axis of rotation, so that the main valve has a fixedtravel. The governor regulates the position of the cut-off eccentric inthe manner hereinbefore described, and the effect of the changes in theposition of the cut-off eccentric'is to cause an earlier or latercut-off, according to the relative positions of the centers of the mainand cut-off eccentrics. The throw, however, of the cut-off eccentric ispractically constant, and the throw of the cut-off valve within or uponthe main valve is practically unchanged in extent, however its period ofmotion may be changed by the changes in the posit-ion of itsactuating-eccentric. For a clearer explanation of this reference is tobe had to the diagram shown in Fig. 5. To avoid complications in thedescription, the said diagram has reference to a construction in whichboth the main and cutoff eccentrics have their eccentricity on the sameside of the shaft A, or, in other words, to a construction in which norocker-arm for the cut-off valve is employed. It will be of courseunderstood that what applies to this construction applies equally wellto a construction where the eccentrics are opposite.

Let a represent the center or axis of rotation of the main shaft, 2 thecrank-pin center, and q the center of the main or fixed eccentric. Letit be supposed that the cut-off eccentric be revolved around the centerq of the main eccentric, so that its center will describe the circle 88' 8 It is obvious that in this case the throw of the cut-off valvewithin or upon the main valve will be unchanged in extent, but willoccur earlier or later with respect to the motion of the main valve,according to the position occupied within the circle .9 s 8 Assumingthat a movement through the are 8 s 3 would cause a variation in thepoint of cut-off of ninety degrees from the beginning of piston-stroke,when the center of the cutoff eccentric is situated at the point 3' thecut-off would occur at half-stroke, and when at s at O or. beginning ofstroke. The same result may be very closely approximated by moving thecenter of the cut-off eecentric through the are 8 3 5 described from thepoint p as a center, instead of from the point q. The variation in thethrow in this latter case is so slight that it practically amounts tonothing. to the pivot c of the arm 0. In either case the motion of thecut-off eccentric is around a point outside of the axis of revolution ofthe main shaft. The diagram in Fig. 5 also shows the movement heretoforeemployed in single valve shifting-eccentric engines. In thisconstruction, q is supposed to represent the center of the shiftingeccentric, and p the point around which it has its governing motion.lVhen the center is at q, the eccentric has its maximum throw, and whenthe center is at q its minimum throw. It will be observed that in thiscase the movement of the eccentric center is practically perpendicularto the radius of the shaft A, while in the movement employed by me themotion of the eccentric center is practically radial to the said shaft.However, when the construction shown in Figs. 1 and 2 is employed thisold movement may be used, although I prefer the one previouslydescribed.

It is obvious that various modifications in the details of constructionand arrangement of parts maybe made without departing from the principleof my invention, and I therefore do not wish to be understood aslimiting myself strictly to the precise details hereinbcfore described,and shown in the drawings.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In a steam engine governor, the com bination, with the shaft andwheel fixed thereon, of a shifting eccentric 011 the shaft, a weightedgovernor-arm secured to the wheel, and a strap-spring connecting thegovernorarm to the eccentric, substantially as and for the purposesspecified.

The point 19 corresponds, of course,

2. In a steam-engine governor, the combination, with the shaft andwheel, of the slotted eccentric and its supporting-arm pivoted to saidwheel, the weighted governorarm pivoted to the wheel, and a strap-springconnecting the governor-arm and eccentric, said governor-arm furnishingthe centrifugal force and said spring furnishing the centripetal force,substantially as and for the purposes specified.-

3. In a steam-engine governor, the combination, with the shaft andwheel, of the slotted eccentric and its supporting-arm, the governor-armconnected to said eccentric by a centripetally-acting flat spring, and aspiral spring of adjustable tension connecting the eccentric and wheeland supplementing the centripetal action of the fiat spring,substantially as and for the purposes specified.

4C. In a steam-engine governor, the combination, with the shaft A andwheel B fixed thereon, of the eccentric O, slotted at c and providedwith hub 0 having arm 0, pivoted to the wheel at c, and arm 0 theweighted governor-arm D, the spring E, connecting said governor-arm andthe arm 0 and the coiled spring F, connected to the arm 0 at one end andadj ustably connected to the wheel by a bolt f at the other end,substantially as and for the purposes specified.

I 5. In a steam-engine governor, the combin ation, with the maineccentric fixed on the shaft, of the cut-off eccentric capable ofmovement across the shaft and having its center of motion at a pointoutside of the axis of the shaft, said cut-off eccentric being soarranged that the path of motion of its center is substantially radialto the shaft, substantially as and for the purposes specified.

EDWIN F. IVILLIAMS.

.Witnesses:

IRVINE MILLER, CARRIE FEIGEL.

